The invention relates to a superconducting cable, comprising a channel for a cooling liquid, a tubular support structure, at least two layers comprising high Tc conductors which comprise a high Tc material, and an insulation, in particular a tubular insulation.
Such a superconducting cable is known from EP 0 623 937 A2, for example.
Superconducting cables are aimed for transporting large currents with a minimum of losses. In general, superconducting cables offer superconducting current paths with a vanishing ohmic resistance. The superconductor material used in superconducting cables must be cooled cryogenically, though. In practice, superconductor materials with a high critical temperature (Tc) are preferred for superconducting cables, such that cooling is possible with inexpensive liquid nitrogen.
However, when transporting alternating current (AC) through a superconducting cable, there will still occur some losses due to eddy currents within the conductors.
S. Takács in Appl. Phys. Lett. 90, 1 (2007), article No. 077724, has found low coupling losses in striated YBCO coated conductors divided by insulating layers and covered with connecting perpendicular, normally conducting metal segments.
It is the object of the invention to provide a superconducting cable exhibiting reduced AC losses, which, accordingly, result in an increased efficiency in the transportation of AC currents through the superconducting cable.